The Place to Start for Operating System Developers
http://f.osdev.org/
All of the code you posted above is wrong!!!Karlosoft wrote:Hi! I've notice a problem. When my kernel is biggest than 50kb, my second stage (part of it, taken by brokenthorn.com) isn't able to load it. i'm using a FAT12 floppy, and the file is correctly loaded in it.
Does anyone have some ideas?
Karlosoft wrote:my second stage [...] isn't able to load it.
Is it or isn't it?Karlosoft wrote:and the file is correctly loaded in it.
I assumed Karlosoft meant "the file is correctly copied into the file system".Hobbes wrote:Karlosoft wrote:my second stage [...] isn't able to load it.Is it or isn't it?Karlosoft wrote:and the file is correctly loaded in it.
That code uses 16-bit registers to keep track of where to load the next sector into RAM. If you call "LoadFile" with BP = 0, then it'll wrap around after 65536 bytes (and if you call "LoadFile" with BP = 0x8000 you'd only be able to load 32 KiB before it fails).Karlosoft wrote:The code of the bootloader-stage2 that load my kernel is the same of this.
Code: Select all
pop cx
pop bx
pop ax
add bx, WORD [bpbBytesPerSector] ; queue next buffer
inc ax ; queue next sector
loop .MAIN ; read next sector
retCode: Select all
pop cx
pop bx
mov ax,es
add ax,512/16
mov es,ax
pop ax
inc ax ; queue next sector
loop .MAIN ; read next sector
ret
. I'm coping my sources on the old.Code: Select all
OUTPUT_FORMAT("binary")
ENTRY(start)
SECTIONS{
.text 0x100000 :
{
code = .; _code = .; __code = .;
*(.text)
. = ALIGN(4096);
}
.data :
{
__CTOR_LIST__ = .; LONG((__CTOR_END__ -
__CTOR_LIST__) / 4 - 2) *(.ctors) LONG(0) __CTOR_END__
= .;
__DTOR_LIST__ = .; LONG((__DTOR_END__ -
__DTOR_LIST__) / 4 - 2) *(.dtors) LONG(0) __DTOR_END__ =
.;
data = .; _data = .; __data = .;
*(.data)
. = ALIGN(4096);
}
.bss :
{
bss = .; _bss = .; __bss = .;
*(.bss)
. = ALIGN(4096);
}
end = .; _end = .; __end = .;
}